Nobody but an eternal boy like Tom would have conceived of a game of stick knife to while away the time of waiting before the mystery hidden by the blank face of the oaken door across the passage. Nobody but an eternal boy would have won so exasperatingly. Expert in all intricacies of the art, Tom had far outdistanced me as a knife juggler and I was lagging far in the rear, when we heard the quiet closing of the door five stories below. In an instant we were on our feet, waiting for the ascending heavy footsteps. Tom’s mobile face stiffened into rigid lines as he crouched, poised beside the door, while I stood ready to swing the door open, and spring if necessary on the man who came. As the footsteps halted on the landing before us, Tom bent towards me. “The assistant,” he whispered, “let him unlock the door and we’ll push our way in with him.” Everything happened in the twinkling of an eye. The jingle of keys, the slight creak of the opening door, then a sudden bound and we were across the hall and in an anteroom facing a bewildered man, evidently a Norwegian, whose blond face was framed in flaxen hair and spade-shaped flaxen beard, and whose somewhat cowlike eyes peered out from spectacles of massive frame. He was clothed in a queer, straight-fronted, long, blue sack coat with voluminous, almost sailor-like trousers. As he saw us standing on either side of him, he started back for a moment, but then stopped short, his keys still dangling from his hand. “Pardon this somewhat sudden entrance,” I said, in my politest tone, “but we are inspectors to visit the laboratory.”